"use strict";

if (!Array.prototype.findIndex) {
  Object.defineProperty(Array.prototype, 'findIndex', {
    value: function value(predicate) {
      // 1. Let O be ? ToObject(this value).
      if (this == null) {
        throw new TypeError('"this" is null or not defined');
      }

      var o = Object(this); // 2. Let len be ? ToLength(? Get(O, "length")).

      var len = o.length >>> 0; // 3. If IsCallable(predicate) is false, throw a TypeError exception.

      if (typeof predicate !== 'function') {
        throw new TypeError('predicate must be a function');
      } // 4. If thisArg was supplied, let T be thisArg; else let T be undefined.


      var thisArg = arguments[1]; // 5. Let k be 0.

      var k = 0; // 6. Repeat, while k < len

      while (k < len) {
        // a. Let Pk be ! ToString(k).
        // b. Let kValue be ? Get(O, Pk).
        // c. Let testResult be ToBoolean(? Call(predicate, T, « kValue, k, O »)).
        // d. If testResult is true, return k.
        var kValue = o[k];

        if (predicate.call(thisArg, kValue, k, o)) {
          return k;
        } // e. Increase k by 1.


        k++;
      } // 7. Return -1.


      return -1;
    },
    configurable: true,
    writable: true
  });
}